Pressure-induced referred pain areas are more expansive in individuals with a recovered fracture

Abstract

Musculoskeletal trauma and pain can sensitize central pain mechanisms, but whether these normalize on recovery is unknown. This study compared the extent of pain referral in individuals recovered from a musculoskeletal trauma and healthy controls. Twenty pain-free participants recovered from a shoulder fracture and 20 age-/sex-matched controls participated in 2 experimental sessions (day-0 and day-1) separated by 24 hours. On both days, pressure pain thresholds were measured bilaterally at infraspinatus, supraspinatus, trapezius, and gastrocnemius muscles. Referred pain towards the shoulder region was induced by a 60-second pressure stimulation (pressure pain threshold + 20%) at the infraspinatus muscle and recorded on an electronic body chart. After day-0 assessments, delayed onset muscle soreness (DOMS) was induced to challenge the pain systems by exercising the external rotators of the recovered/dominant shoulder. The size of pressure-induced pain referral on day-0 did not differ between groups, although there was a tendency for a smaller referred pain area in recovered group. Pressure pain thresholds at the infraspinatus muscle on the DOMS side were reduced on day-1 in both groups (P = 0.03). An expansion of pressure-induced pain referral was found in both groups following the DOMS protocol on day-1 (P = 0.05) with a relatively larger expansion (P = 0.05) and higher frequency of pain in the shoulder (P = 0.04) in the recovered pain group. After complete recovery and absence of pain symptoms after a fracture, central pain mechanisms seem to normalize in the region of the trauma after recovery but when sensitized a heightened response can emerge. Such mechanisms could be important for recurrence of pain conditions.

The Area of Pressure-Induced Referred Pain Is Dependent on the Intensity of the Suprathreshold Stimulus: An Explorative Study

“…This may, however, not be feasible due to the invasive nature of the procedure and calls for alternative methods for inducing referred pain. In that respect, applying a tonic, nociceptive pressure stimulus on somatic structures is known to effectively induce referred pain in healthy individuals [7,8,10,11]. Furthermore, sensitizing the area by way of, for example, inducing exercise-related muscle soreness (delayed onset of muscle soreness [DOMS]) prior to stimulating it results in a pain referral pattern of a greater area [12], resembling what is seen following a hypertonic saline injection [7,13].…”

“…Furthermore, sensitizing the area by way of, for example, inducing exercise-related muscle soreness (delayed onset of muscle soreness [DOMS]) prior to stimulating it results in a pain referral pattern of a greater area [12], resembling what is seen following a hypertonic saline injection [7,13]. Considering that pain referral seems to be facilitated in persons suffering from chronic pain [4,12] and in people who have recovered from a musculoskeletal injury [10,14], inducing muscle soreness is a surrogate pain model to investigate referred pain.…”

Effect of Transversus abdominis muscle training on pressure-pain threshold in patients with chronic low Back pain

“…Pain tolerance measurement involved 120% PPT continuous stimulation at the erector spinae measurement point for 1 minute [36]. During the test, the subjects were asked to pay attention to the nature of Fig.…”

“…Then, they were asked to answer the figure of body surface pain radiation [37] (Fig. 7) and the short-form McGill pain questionnaire [36] immediately. The subjects were asked to circle the pain range on the figure of body surface pain radiation, and the data were evaluated in accordance with the number of grids circled by the subject.…”

Measures of central sensitization and their measurement properties in musculoskeletal trauma: A systematic review

“…Chronic pain and poorer recovery are common following musculoskeletal trauma (Carroll et al., 2008; Rivara et al., 2008; Williamson et al., 2009). In chronic whiplash associated disorders (WAD), poorer outcome is linked to early widespread sensitization (Sterling et al., 2003; Van Oosterwijck et al., 2013; Walton, MacDermid, Nielson, Teasell, Reese, et al., 2011), and following fractures, widespread pain distribution is evident soon after injury (Doménech‐García et al., 2018). Due to noxious stimuli and prolonged duration of high pain intensity (Graven‐Nielsen & Arendt‐Nielsen, 2010; Katz & Seltzer, 2009), hypersensitivity of the central nervous system or central sensitization (CS) could occur in this population.…”